Per Medscape: CHF is when "the heart, via an abnormality of cardiac function (detectable or not), fails to pump blood at a rate commensurate with the requirements of the metabolizing tissues or is able to do so only with an elevated diastolic filling pressure"
Some Generalities:
S3 = most specific exam finding (Ken-tucky, Ken-tucky)
Edema = most specific CXR finding . .
BNP : below 100 pg/ml?? -- > basically rules out CHF (90% specificity)
above 500 pg/ml? --> most likely acute decompensated CHF (87% specificity) .
Scenarios:
Isolated left sided failure --> dyspnea, fatigue, orthopnea (WITHOUT peripheral edema or JVD).
Isolated right sided failure --> JVD, hepatojugular reflex, peripheral edema (with clear lungs sounds/CXR).
Right sided failure most common caused by left sided failure.
Systolic failure = poor contraction (low EF) and less forward blood flow
Diastolic failure = Good contractility (normal ish EF) with poor filling 2/2 stiff ventricles
NYHA Classes
No symptoms
Symptoms with every day activity
Severely limits activity or symptoms with minimal activity
Symptoms at rest
Test Pearls:
Acute CHF with STEMI on EKG --> go directly to Cath lab
Acute CHF with new systolic murmur (particular after an inferior or posterior MI) --> think Cordae Tendinae rupture --> mitral valve regurgitation 2/2 posterior leaflet of valve supplied by right coronary artery (this patient needs cardiothoracic surgery ASAP!!)
Acute CHF with syncope and/or heart murmur --> think aortic stenosis in elderly, think HOCM in the young.
Acute CHF with right sided MI --> concern for RV infarct --> fluids and/or dobutamine only if hypotensive (DO NOT TREAT LIKE TYPICAL CHF aka Nitrites and diuretics)
Acute CHF in dialysis patient with AV fistula --> think high output failure through fistula --> compress fistula site manually to decrease shunting of blood through fistula. Other types of high output failure can be seen in pregnancy, hyperthyroidism, beriberi
Obviously a tremendous topic, just scratching the surface here. Stay tuned for more POTD coming up.
Sources: In training prep video - Cardiology
https://emedicine.medscape.com/article/354666-overview#a2